libera_utils.footprint_matching.psf.PSFAngularExtent#

class libera_utils.footprint_matching.psf.PSFAngularExtent(delta_back_deg: float, delta_front_deg: float, beta_max_deg: float)#

Half-extents of the PSF response in the instrument angular frame (degrees).

The footprint’s angular reach is split into three numbers because the PSF is not a simple disc:

The along-scan (delta) extent is asymmetric – the detector time-response tail (ATBD Eq. 4.4-2) trails the scan, so the response reaches further on one side of the centroid than the other. delta_back_deg and delta_front_deg are the (positive) half-extents toward -delta and +delta respectively.
The cross-scan (beta) extent is symmetric because the PSF obeys P(delta, beta) = P(delta, -beta) (ATBD Eq. 4.4-1), so a single beta_max_deg describes both sides.

Variables:

delta_back_deg (float) – Half-extent toward negative along-scan angle (degrees, >= 0).
delta_front_deg (float) – Half-extent toward positive along-scan angle (degrees, >= 0).
beta_max_deg (float) – Symmetric cross-scan half-extent (degrees, >= 0).

__init__(delta_back_deg: float, delta_front_deg: float, beta_max_deg: float) → None#